300TDi Turbo Model Gen info?

G'Day All,
Just wondering if you can tell us what model and Brand of Turbo is in our 98 Disco please?

Also Ive been wanting to read up on turbos for a while, and after talking to a workmate I thought I would do just that.....So does anybody know of a good site where I can read up on Turbos mainly to do with Diesel's, just basic stuff ie how, why,when etc